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Overview

A tornado struck Delavan, in southern Tazewell County, late in the evening of July 16th. Reports indicate that 51 homes were damaged by this tornado, six of which were determined to be a total loss. While there were no fatalities, there were two injuries. Delavan tornado damage. Image courtesy of Illinois State Police.
Damage in Delavan. Image courtesy of Illinois State Police.

Tornadoes:

Tornado - DELAVAN
Tazewell County

Date 7/16/2015
Time (Local) 11:39 pm - 11:40 pm
EF Rating EF-2
Est. Peak Winds 120 mph
Path Length 1.3 miles
Max Width 250 yards
Injuries/Deaths 2 injured, 0 deaths

Summary:

The tornado rapidly developed on the southwest edge of Delavan at 11:39 pm. It moved to the east-northeast, severely damaging a home and several outbuildings. As it moved into the southern part of the town at 11:41 pm, it reached its maximum width of 250 yards. It rapidly decreased in width and intensity as it damaged trees and grave markers at the Prairie Rest Cemetery. The tornado crossed Springfield Rd. and then dissipated in a field at 11:43 pm. A total of 51 home were damaged in Delavan, 15 severely; the severely damaged homes had the roof torn off or a majority of the roof deck lifted off. Numerous garages, outbuildings and trees were also damaged.

Storm damage in Delavan. Image courtesy of Illinois Emergency Management Agency. Delavan tornado damage. Image courtesy of Illinois Emergency Management Agency. Tornado damage. Image courtesy of Illinois Emergency Management Agency. Tornado damage. Image courtesy of Illinois Emergency Management Agency.
Image courtesy of IEMA Image courtesy of IEMA Image courtesy of IEMA Image courtesy of IEMA
 

 

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0
Weak

65-85 mph
EF1
Moderate
86-110 mph
EF2
Significant
111-135 mph
EF3
Severe
136-165 mph
EF4
Extreme
166-200 mph
EF5
Catastrophic
200+ mph
ef-scale

Radar:

Images from Lincoln Doppler radar

Here is the radar presentation of the storm from 11:36 pm. The image on the left is the reflectivity image; the curved area from northwest to southwest of Delavan shows the storm's rear flank downdraft.  On the right is the storm relative motion (i.e. the actual Doppler part of the radar), showing a circulation having just formed 1 mile southwest of Delavan (inside the yellow circle). Reports from the town indicate that the tornado struck there at 11:39 pm.  (Click images to enlarge.)

Reflectivity image from 11:36 pm Storm Relative Motion image from 11:36 pm
Reflectivity image Storm Relative Motion image

Additional Information:


Watches and Warnings

A Severe Thunderstorm Watch was issued at 4:55 pm, which was in effect through midnight. 

Why no warning?  Due to how fast this tornado developed and dissipated, the circulation was gone by the time a warning could have been issued.  Local emergency officials saw a funnel and tried to sound the outdoor warning sirens, but the tornado cut off power to the town and the sirens were silenced after a couple seconds. 

 

Delavan Tornado History

Information from the Storm Prediction Center and the National Centers for Environmental Information (NCEI) indicate 11 tornadoes have occurred across far southern part of Tazewell County since detailed records became available in 1950.  Two of these came closest to Delavan:

  • April 16, 1960:  A tornado touched down during the early afternoon and damaged a few farmsteads southwest of Delavan. This tornado was rated at F1 intensity.
  • June 4, 1999:  This tornado touched down on the northwest side of Delavan, uprooting several trees.Some building damage was also noted in Delavan, especially due to falling tree limbs. The tornado was on the ground for 3 miles before dissipating southeast of town. It also was rated at F1 intensity.

Tazewell County tornado climatology

More detailed information regarding Tazewell County tornado history can be found by clicking here.

 


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